If you are invited for a network engineer interview, you should answer a couple of questions before you start preparing for the big day:
What technology does the employer prefer? Do they use Cisco, or Juniper for their networks? Do they go for speed, or for security? What kind of networks do they run (or design for their clients)?
Technical interview questions will vary in each case, and to have a chance to prepare for them, at least somehow, you need to know their favorite technology.
Questions will depend also on the interviewer, and stage of the interview process
Who is going to lead the interview with you is another important question. Interview process consists typically of several rounds.
In the first one, external recruiter, or an HR generalist, will interview you. They will know absolutely nothing about Cisco, Juniper and network engineering in general.
Their goal is to assess your motivation, your communication skills, and get a good grasp of your personality. This is called screening interview, and you have to pass it to progress to the next round. You will get some of the following questions:
- Why did you choose a career in network engineering?
- What attracts you the most on this field?
- Why do you want to work for our company and not somewhere else?
- Why do you prefer employment to freelancing?
- What are your strengths and weaknesses?
- What motivates you the most in your job?
- Can you tell me something about your experience?
- Where do you see yourself in five years time?
Next round (bear in mind that they can conduct all rounds at once, or each round separately) typically consists in behavioral questions, which aren’t technical again. In this stage the interviewers try to understand your attitude to various work related situations.
How do you handle pressure? How do you handle conflicts with your colleagues? Can you meet tight deadlines, and how do they impact the quality of your work?
You will deal with the following questions, and some more:
- Describe a situation when you had to meet a tight deadline. How did you ensure you’d meet the deadline?
- Describe a conflict you had with your boss, or with your colleague. What was the reason for the conflict? What did you do to solve the conflict?
- Describe a situation when you were forced to work under pressure. How did you cope with the situation?
- Describe a time you struggled to communicate a technical issue to someone without technical knowledge.
Technical questions – final stage of an interview
Finally, once you manage to make a good impression on the HR people, you will progress to the final stage of the interview process. IT specialist, or senior network engineer, will typically lead this interview. Most of the time at least one person from HR will be present in a room as well, and you will interview in front of a small panel (two to four people).
In this stage, you will deal mostly with technical questions. See some below:
- Why do you prefer Cisco (Juniper) to other solutions?
- Can you name the advantages of Cisco (Juniper)?
- What Firewall do you personally consider the most secure one and why?
- Do you know what means to bridge the VPNs? Where do we use it?
- What is the reason why we should use secondary router also?
- What are the layers in TCP/IP protocol?
- Can you define various types of Sockets and where we can find them?
- What means the following address of subnet mask?
- What represents the majority part of worldwide NSP revenue today?
- How would you reduce the watts per bit to ensure the higher efficiency of a computer network? Describe the process and the steps you would take.
- Describe the last time you had to troubleshoot a network. What was the problem and what steps did you take to eliminate the problem?
- What do you see as future of network engineering?
- From your point of view, what is more important nowadays: security or speed?
- Write a function, and the output should be the function itself.
- When you receive a crash dump for a process from a particular customer, Is it possible to know the line number of which function has caused the problem?
As you can probably guess, there are thousands of technical questions they can ask you in an interview. To be honest, nobody can answer all of them, and it is difficult to prepare for this part of an interview in advance.
The most important thing, however, is to show the interviewers that you know what you are talking about, and that you can find a solution to a problem (searching the forums, doing split tests, etc).
What decides the winner at the end of the interviews?
The competition is never super high in this interview.
However, the few applicants who compete with you for the job will typically have good knowledge of the technology, and they will handle the technical questions (so will you).
Therefor it is often an ability to sell your skills and knowledge to the interviewers, and your answers to screening and behavioral questions, that makes the difference at the end of the interviews…
I know that many great engineers struggle exactly with that–with the answers to non-technical questions, and with their effort to make a good impression.
If you belong to this group, and would like to learn how to do it right, how to gain confidence and make a great impression on your interviewers, have a look at my I Will Get a Job recording. I will teach you how to ace your interview, in just sixty minutes.
(*Since January 2018, I added answers to thirty most common screening and behavioral questions to the recording, just to ensure you will succeed. Thank you for checking it out here, and good luck in your interview!
Matthew Chulaw, Professional Interview Coach & Recruitment Consultant, author of the website.